GINKGOALBS 



39 



In 1869 Van Tiegliem ^ published his view that the stalk 

 represents a petiole, and that the two OYiales are determined by 

 the two characteristic lobes of the blade. According to this 

 view, the whole structure stands for a single carpel. Van 

 Tieghem further sees in the collar at the base of each ovule a 

 reduced arillus, which name of course gives no clew to its 

 homology. In 18Y2 Strasburger^ published the view that 

 the stalk is a shoot, and that the collar is the rudiment of the 

 first pair of leaves of a secondary shoot. It would follow that 

 the whole structure is an inflorescence bearing two flowers, and 



Pig. 30. — Giiihgo liloba: A, dwarf branch bearing leaves and young ovules; B, a stara- 

 inate strobilus ; C, more enlarged view of a portion of .B ; D, longitudinal section of 

 a young ovule ; £, a ripe seed associated with an undeveloped ovule. A, B, E, 

 natural size ; C, D, enlarged. — After Goebel. 



that any such structure as a carpel is suppressed. In 1879 ^ 

 he modified his view as to the character of the collar, having 

 concluded, as Van Tieghem had thought, that it represents an 

 arillus. He cited cases in which a stalk bore four ovules, each 

 upon a slender stalk of its own; this of course was a strong 

 argument in favor of the view that the whole structure repre- 

 sents a shoot. In 1873 Eichler * published his view that the 

 collar represents an outer integument, which is not necessarily 

 inconsistent with the preceding views that it stands for an 

 arillus. Later '^ he called the collar a rudimentary carpel, and 



